Pharmacological properties
Pharmacodynamics. Terbinafine is an allylamine and has a broad spectrum of antifungal activity. Terbinafine at appropriate concentrations exhibits fungicidal activity against dermatophytes, molds and some dimorphic fungi. Activity against yeasts, depending on their species, can be fungicidal or fungistatic.
Terbinafine specifically inhibits the early stage of sterol biosynthesis in the fungal cell membrane. This leads to ergosterol deficiency and intracellular accumulation of squalene, which causes fungal cell death. Terbinafine exerts its effect by inhibiting the squalene epoxidase enzyme in the fungal cell membrane. This enzyme does not belong to the cytochrome P450 system. Terbinafine does not affect the metabolism of hormones or other drugs.
When applied topically, the drug begins to act quickly, and it can be used to achieve an effect with short-term treatment (7-14 days).
With topical application, less than 5% of the dose is absorbed, so the absorption of terbinafine into the systemic bloodstream is insignificant.
Pharmacokinetics: Not studied.
Indication
Fungal skin infections caused by dermatophytes such as Trichophyton (e.g. T. rubrum, T. mentagrophytes, T. verrucosum, T. violaceum), Microsporum canis and Epidermophyton floccosum, e.g. interdigital tinea pedis ("athlete's foot"), inguinal tinea ("jockey's itch"), truncal tinea (ringworm). Tinea versicolor caused by Pityrosporum orbiculare (also known as Malassezia furfur).
Application
The duration of treatment depends on the type of disease and its severity.
The gel is applied to the skin once a day. Before applying the gel, it is necessary to clean and dry the affected areas of the skin. The gel is applied in a thin layer to the affected skin and adjacent areas and rubbed in lightly. In infections accompanied by diaper rash in skin folds (under the mammary glands, between the fingers, between the buttocks, in the groin area), the areas with the applied gel can be covered with gauze, especially at night.
Average duration of treatment:
- athlete's foot (interdigital): 1 time per day for 1 week; - inguinal ringworm and trunk ringworm: 1 time per day for 1 week; - lichen varicolor: 1 time per day for 1 week.
Dosage adjustment of the drug is not required in the elderly.
Contraindication
Hypersensitivity to terbinafine or any component of the drug.
Side effects
Local manifestations such as itching, peeling or burning of the skin, pain and irritation at the application site, pigmentation disorders, erythema, crusting and others may be observed at the application site. These minor manifestations should be distinguished from hypersensitivity reactions, including rashes, which have been reported in isolated cases and require discontinuation of treatment. In case of accidental contact with the eyes, terbinafine may cause eye irritation. In rare cases, latent fungal infections may be exacerbated.
Possible side effects
Immune system disorders: hypersensitivity reactions, including urticaria.
From the organs of vision: eye irritation.
Skin and connective tissue disorders: skin peeling, itching, skin damage, crusting, skin lesions, pigmentation disorders, erythema, burning sensation of the skin, dry skin, contact dermatitis, eczema, rash.
General disorders and administration site conditions: pain, application site pain, application site irritation, worsening of symptoms.
Special instructions
The drug should be prescribed with caution to patients with facial lesions. The gel is intended for topical application to the skin only. Avoid contact with the eyes. If the gel gets into the eyes, rinse them with running water.
Usually, relief of clinical symptoms occurs within a few days. Irregular use of the drug or untimely discontinuation of treatment may lead to a relapse of the disease.
To prevent skin mycosis, it is necessary to adhere to the following rules: change underwear daily, since microorganisms may be present on parts of clothing that have been in contact with infected skin surfaces; avoid wearing clothing that is too tight or poorly permeable to air; thoroughly dry the affected areas of the skin after washing; change your personal towel every day. With foot mycosis, walking barefoot is contraindicated. In addition to local treatment, it is recommended to treat the inside of socks or shoes with an appropriate antifungal agent once a day.
Use during pregnancy and breastfeeding. Since clinical experience with the use of the gel in women during pregnancy and breastfeeding is very limited, it can be used during this period only if the benefit of treatment for the mother outweighs the potential risk to the fetus/child.
When performing topical treatment, it is unlikely that the small amount of active substance that is absorbed through the skin will have a negative effect on the fetus.
Terbinafine penetrates into breast milk in small amounts, so the drug should not be used during breastfeeding.
The child should be avoided from coming into contact with any area of skin where the medicine has been applied.
Children. Due to insufficient experience, the use of Lamifen gel in children is not recommended.
The ability to influence the reaction rate when driving vehicles or other mechanisms is unknown.
Interactions
Unknown.
Low systemic absorption of terbinafine in the form of a gel for topical use makes overdose extremely unlikely. In case of accidental internal use of the drug, the following side effects should be expected, as in the case of an overdose of the drug Lamifen in the form of tablets: headache, nausea, epigastric pain and dizziness. Symptomatic therapy. In case of gel ingestion, induce vomiting if necessary.
Storage conditions
At a temperature not exceeding 25 °C; Do not freeze.
